US President Barack Obama was looking to put the seal on his European charm offensive Sunday as the guest of honour at an EU summit in Prague where he is set to roll out plans to ease nuclear tensions.

On the third leg of a maiden European tour as president, Obama was in the Czech Republic whose prime minister recently branded the White House's plans to revive the US economy as "a road to hell".

But any offence taken by the undiplomatic language of his hosts is likely to be buried by Obama who has won over Europe's major leaders on his trips to London for a G20 summit and a NATO gathering hosted by France and Germany.

"I find it extraordinarily hopeful for the future that the partnership that we are developing with President Obama, and the partnership the rest of Europe finds it has with President Obama, is genuinely a partnership of purpose," British Prime Minister Gordon Brown said Saturday after the Nato summit.

"We are not just talking, we are agreeing decisions."

Obama's intervention was seen as key to Turkey dropping its opposition to Danish Prime Minister Anders Fogh Rasmussen becoming Nato's new leader at the alliance's summit where it was also agreed to build better ties with Russia.

According to US officials, Obama will make a major address at Prague Castle on the issue of nuclear proliferation in a country which, along with Poland, is due to host a nuclear missile shield project.

On Friday, in Strasbourg, Obama said reducing the threat of weapons of mass destruction was one of the top two goals for his presidency, along with rescuing the US economy.

"I would like to be able to say that as a consequence of my work, that we drastically lessened the threat of not only terrorism but also nuclear terrorism.

"And we can't reduce the threat of a nuclear weapon going off unless those who possess the most nuclear weapons — the United States and Russia — take serious steps to actually reduce our stockpiles.

"We want to pursue that vigorously in the years ahead. And I had a excellent meeting with President (Dmitry) Medvedev of Russia to get started that process of reducing our nuclear stockpiles, which will then give us greater moral authority to say to Iran, don't develop a nuclear weapon; to say to North Korea, don't proliferate nuclear weapons."

North Korea is due to test fire a missile any day now, despite Obama's warning that such a move would be seen as provocative.

Although Medvedev said no serious progress was made at his first talks with Obama in London on Wednesday, the Czechs are fearful that a warming in ties between Washington and Moscow could see the shield plan dropped.

Czech Deputy Premier Alexandr Vondra told AFP last week he did not expect the United States to scrap its missile shield plans, despite Obama's decision to review the scheme which Moscow opposes.

"It's up to the Americans to say what their ideas are," he said.

The shield project was officially devised by Obama's predecessor George W. Bush to defend against long-range ballistic missiles possibly fired by "rogue states" such as Iran, but Moscow views it as a threat to Russian security.

While the Czechs have been choosing their words carefully on the missile shield, Prime Minister Mirek Topolanek has made little effort to disguise his opposition to Obama's spending plans, telling EU lawmakers last month they represented the "road to hell".

The White House brushed off Topolanek's comments as being for domestic consumption, coming the day after his government was defeated in a no-confidence motion.

The summit was to have been the icing on the cake of the Czechs' six-month EU presidency, but Topolanek's domestic political woes have hampered his ability to speak on behalf of the 27-nation bloc.

Brown, host of Thursday's G20 summit in London, is expected to take the lead role in the EU's economic talks with Obama.

Swedish Prime Minister Fredrik Reinfeldt and Spanish counterpart Jose Luis Zapatero, whose countries are next in line to assume the EU presidency, are set to head the debate on climate change, according to diplomats.

Obama's visit has turned Prague's historic centre into a well-guarded fortress with 4000 police officers on duty. There is a rally protesting the US missile shield, scheduled for Sunday afternoon.

After the summit, Obama heads to Turkey on the final leg of what is his first trip as president outside North America.